Cost-eff ectiveness of community-based screening and treatment for chronic hepatitis B in The Gambia: an economic modelling analysis

Background Despite the high burden of hepatitis B virus (HBV) infection in sub-Saharan Africa, absence of widespread screening and poor access to treatment leads to most people remaining undiagnosed until later stages of disease when prognosis is poor and treatment options are limited. We examined the cost-eff ectiveness of community-based screening and early treatment with antiviral therapy for HBV in The Gambia. Methods In this economic evaluation, we combined a decision tree with a Markov state transition model to compare a screen and treat intervention consisting of adult community-based screening using a hepatitis B surface antigen (HBsAg) rapid test and subsequent HBV antiviral therapy versus current practice, in which there is an absence of publicly provided screening or treatment for HBV. We used data from the PROLIFICA study to parameterise epidemiological, primary screening, and cost information, and other model parameter inputs were obtained from a literature search. Outcome measures were cost per disability-adjusted life-year (DALY) averted; cost per life-year saved; and cost per quality-adjusted life-year (QALY) gained. We calculated the incremental cost-eff ectiveness ratios (ICERs) between current practice and the screen and treat intervention. Costs were assessed from a health provider perspective. Costs (expressed in 2013 US$) and health outcomes were discounted at 3 Findings In The Gambia, where the prevalence of HBsAg is 8·8 treatment for HBV has an incremental cost-eff ectiveness ratio (ICER) of$540 per DALY averted, $645 per life-year saved, and$511 per QALY gained, compared with current practice. These ICERs are in line with willingness-to-pay levels of one times the country’s gross domestic product per capita ($487) per DALY averted, and remain robust over a wide range of epidemiological and cost parameter inputs. Interpretation Adult community-based screening and treatment for HBV in The Gambia is likely to be a cost-eff ective intervention. Higher cost-eff ectiveness might be achievable with targeted facility-based screening, price reductions of drugs and diagnostics, and integration of HBV screening with other public health interventions

Clinical characteristics and outcomes of patients with cirrhosis and hepatocellular carcinoma in The Gambia, west Africa: a prospective cohort study.

BACKGROUND: Chronic liver disease is a major cause of premature death in sub-Saharan Africa. Efficacy of antiviral therapy among patients with hepatitis B virus (HBV)-related cirrhosis is not well established in Africa. We described the clinical characteristics and outcomes of patients with cirrhosis and hepatocellular carcinoma in The Gambia and assessed the impact of tenofovir disoproxil fumarate (TDF) on survival of HBV-infected patients with cirrhosis. METHODS: In this prospective cohort study, we followed up adults who were consecutively diagnosed with cirrhosis or hepatocellular carcinoma between 2012 and 2015 in The Gambia, west Africa. Patients with chronic HBV infection and cirrhosis, without hepatocellular carcinoma, were offered TDF. Primary outcome was overall survival. To determine the effect of TDF on survival, we performed a Cox proportional hazard regression model with inverse probability of treatment weighting (IPTW) based on propensity score. FINDINGS: Of 529 patients enrolled in this study, 336 patients (252 with hepatocellular carcinoma and 84 with cirrhosis) were analysed. Patients were predominantly male (253 [75%] men and 83 [25%] women), with a median age of 42 years (IQR 33-55). 276 (84%) of 327 of patients with data were positive for HBV biomarkers, 31 (10%) of 311 were positive for hepatitis C virus antibodies, and 22 (10%) of 223 were positive for hepatitis D virus antibodies. 64% of patients with hepatocellular carcinoma had multifocal tumour, with a median size of 7·5 cm (IQR 5·4-10·8). 173 patients with hepatocellular carcinoma and 70 patients with cirrhosis were included in the survival analysis. Median survival was 1·5 months (95% CI 1·1-2·0) in patients with hepatocellular carcinoma and 17·1 months (11·2-24·0) in patients with cirrhosis (log-rank p<0·0001). In patients with hepatocellular carcinoma, ascites (hazard ratio [HR] 1·78, 95% CI 1·21-2·60), partial or complete portal thrombosis (HR 2·61, 1·58-4·30), and platelet count (HR 1·80, 1·19-2·70) were independent predictive factors of mortality at baseline. In HBV-infected patients with cirrhosis, median turnaround time between cirrhosis diagnosis and TDF initiation was 4·9 months (IQR 3·2-7·3). In IPTW analysis, TDF treatment was associated with improved survival in patients with HBV-related cirrhosis (adjusted HR 0·14, 0·06-0·34; p<0·0001). INTERPRETATION: These results highlight poor survival of patients with cirrhosis or hepatocellular carcinoma as well as the effectiveness of TDF in reducing the premature mortality of patients with cirrhosis and HBV infection. Interventions for early diagnosis and treatment of cirrhosis as well as screening programmes for hepatocellular carcinoma are urgently required in Africa. FUNDING: European Commission and Medical Research Council UK. TRANSLATION: For the French translation of the abstract see Supplementary Materials section

Acceptability and feasibility of a screen-and-treat programme for hepatitis B virus infection in The Gambia: the Prevention of Liver Fibrosis and Cancer in Africa (PROLIFICA) study.

BACKGROUND: Despite the introduction of immunisation for hepatitis B virus (HBV) in the 1990s, HBV-related morbidity and mortality remain high in sub-Saharan Africa. Identification and treatment of asymptomatic people with chronic HBV infection should reduce the disease burden. We therefore assessed the feasibility of a screen-and-treat programme for HBV infection in The Gambia, west Africa, and estimated the proportion of HBV-infected people who had significant liver disease in need of treatment. METHODS: Between Dec 7, 2011, and Jan 24, 2014, individuals living in randomly selected communities in western Gambia were offered hepatitis B surface antigen (HBsAg) screening via a point-of-care test. The test was also offered to potential blood donors attending the central hospital in the capital, Banjul. HBsAg-positive individuals were invited for a comprehensive liver assessment and were offered treatment according to international guidelines. We defined linkage to care as visiting the liver clinic at least once. Eligibility for treatment was judged in accordance with the 2012 European Association for the Study of the Liver guidelines. FINDINGS: HBsAg screening was accepted by 5980 (weighted estimate 68·9%, 95% CI 65·0-72·4) of 8170 adults from 27 rural and 27 urban communities and 5559 (81·4%, 80·4-82·3) of 6832 blood donors. HBsAg was detected in 495 (8·8%, 7·9-9·7) individuals in communities and 721 (13·0%, 12·1-13·9) blood donors. Prevalence was higher in men (239 [10·5%, 8·9-12·1] of 2328 men vs 256 [7·6%, 6·5-8·7] of 3652 women; p=0·004) and middle-aged participants. Linkage to care was high in the communities, with 402 (81·3%) of 495 HBsAg-positive individuals attending the clinic. However, only 300 (41·6%) of 721 HBsAg-positive people screened at the blood bank linked into care. Of those who attended the clinic, 18 (4·4%, 2·5-7·7) patients from the communities and 29 (9·7%, 6·8-13·6) from the blood bank were eligible for treatment. Male sex was strongly associated with treatment eligibility (odds ratio 4·35, 1·50-12·58; p=0·007). INTERPRETATION: HBV infection remains highly prevalent in The Gambia. The high coverage of community-based screening, good linkage into care, and the small proportion of HBsAg carriers who need treatment suggest that large-scale screening and treatment programmes are feasible in sub-Saharan Africa. FUNDING: European Commission (FP7)

[Prevention of liver fibrosis and liver cancer linked to hepatitis B virus in Africa: the Prolifica study].

Despite the existence of an effective vaccine, HBV infects 257 million people worldwide and is the cause of the majority of HCC. With an annual mortality rate of 887 000 patients in 2015, this cancer is the second deadliest. Low-income countries such as ones in sub-Saharan Africa are the most at risk due to the limited access to healthcare. To overcome this and born from an international research collaboration within an EU project, the Prolifica study aimed at evaluating a screen-and-treat program to prevent HBV complications, and more particularly HCC. Based on communities, facilities and hospitals HBsAg+ detection, the study lasted from 2011 to 2016. From the "cost effectiveness" feasibility of such a program to the development of simple scores for antiviral treatment, Prolifica uncovered data of crucial importance in a region with low HBV infection awareness, transmissions modes and prevention means which could have impacts on public health policies

Cost-effectiveness of community-based screening and treatment for chronic hepatitis B in The Gambia: an economic modelling analysis.

Background: Despite the high burden of hepatitis B virus (HBV) infection in sub-Saharan Africa, absence of widespread screening and poor access to treatment leads to most people remaining undiagnosed until later stages of disease when prognosis is poor and treatment options are limited. We examined the cost-effectiveness of community-based screening and early treatment with antiviral therapy for HBV in The Gambia. Methods: In this economic evaluation, we combined a decision tree with a Markov state transition model to compare a screen and treat intervention consisting of adult community-based screening using a hepatitis B surface antigen (HBsAg) rapid test and subsequent HBV antiviral therapy versus current practice, in which there is an absence of publicly provided screening or treatment for HBV. We used data from the PROLIFICA study to parameterise epidemiological, primary screening, and cost information, and other model parameter inputs were obtained from a literature search. Outcome measures were cost per disability-adjusted life-year (DALY) averted; cost per life-year saved; and cost per quality-adjusted life-year (QALY) gained. We calculated the incremental cost-effectiveness ratios (ICERs) between current practice and the screen and treat intervention. Costs were assessed from a health provider perspective. Costs (expressed in 2013 US$) and health outcomes were discounted at 3$540 per DALY averted, $645 per life-year saved, and$511 per QALY gained, compared with current practice. These ICERs are in line with willingness-to-pay levels of one times the country's gross domestic product per capita ($487) per DALY averted, and remain robust over a wide range of epidemiological and cost parameter inputs. Interpretation: Adult community-based screening and treatment for HBV in The Gambia is likely to be a cost-effective intervention. Higher cost-effectiveness might be achievable with targeted facility-based screening, price reductions of drugs and diagnostics, and integration of HBV screening with other public health interventions

Prevalence and Clinical Significance of Occult Hepatitis B Infection in The Gambia, West Africa

International audienceAbstract Background Prevalence and clinical outcomes of occult hepatitis B infection (OBI) have been poorly studied in Africa. Methods Using the PROLIFICA cohort, we compared the prevalence of OBI between hepatitis B surface antigen (HBsAg)-negative healthy adults screened from the general population (controls) and HBsAg-negative patients with advanced liver disease (cases), and estimated the population attributable fraction for the effect of OBI on advanced liver disease. Results OBI prevalence was significantly higher among cases (15/82, 18.3%) than controls (31/330, 9.4%, P = .03). After adjusting for age, sex, and anti-hepatitis C virus (HCV) serology, OBI was significantly associated with advanced liver disease (odds ratio, 2.8; 95% confidence interval [CI], 1.3–6.0; P = .006). In HBsAg-negative people, the proportions of advanced liver disease cases attributable to OBI and HCV were estimated at 12.9% (95% CI, 7.5%–18.1%) and 16.9% (95% CI, 15.2%–18.6%), respectively. Conclusions OBI is endemic and an independent risk factor for advanced liver disease in The Gambia, West Africa. This implies that HBsAg-negative people with liver disease should be systematically screened for OBI. Moreover, the impact of infant hepatitis B immunization to prevent end-stage liver disease might be higher than previous estimates based solely on HBsAg positivity

Birth order and risk of hepatocellular carcinoma in chronic carriers of hepatitis B virus: a case-control study in The Gambia.

BACKGROUND & AIMS: Early age at infection with Hepatitis B virus (HBV) increases the risk of chronic infection. Moreover, early HBV infection may further independently increase the risk of hepatocellular carcinoma (HCC) beyond its effect on chronicity. METHODS: The distribution of birth order, a proxy for mode and timing of HBV transmission, was compared in The Gambia between hepatitis B surface antigen (HBsAg)-positive HCC cases recruited from hospitals (n = 72) and two HBsAg-positive control groups without HCC: population-based controls from a community HBV screening (n = 392) and hospital-based controls (n = 63). RESULTS: HCC risk decreased with increasing birth order in the population-based case-control analysis. Using first birth order as the reference, the odds ratios were 0.52 (95% CI: 0.20-1.36), 0.52 (0.17-1.56), 0.57 (0.16-2.05) and 0.14 (0.03-0.64) for second, third, fourth and greater than fourth birth order respectively (P = 0.01). A similar inverse association was observed in the hospital-based case-control comparison (P = 0.04). CONCLUSIONS: Compared to controls, HCC cases had earlier birth order, a proxy for young maternal age and maternal HBV viraemia at birth. This finding suggests that in chronic HBV carriers perinatal mother-to-infant transmission may increase HCC risk more than horizontal transmission. Providing HBV vaccine within 24 h of birth to interrupt perinatal transmission might reduce the incidence of HCC in The Gambia

Clinical manifestation, staging and prognosis of hepatocellular carcinoma in Gambian patients

Abstract Background As a result of the lack of screening programs and the difficulty in making a proper diagnosis, the majority of hepatocellular carcinoma (HHC) patients present late in low-resource countries. The study therefore assesses the clinical features, stage and prognostic variables of patients with HCC in The Gambia. Methods From December 2015 to January 2019, patients with a confirmed diagnosis of HCC were enrolled. All patients’ medical history, ultrasound scan, FibroScan and laboratory details were collected. Results Two hundred and sixty (260) patients were enrolled. The mean age of HCC patients was 40 years, and 210 (80.7%) of them were male. The most common gastrointestinal symptoms were early satiety 229 (88.1%) and abdominal pain 288 (87.7%), while the most common constitutional symptoms were weight loss 237 (91.2%) and easy fatiguability 237 (91.2%). Hepatomegaly 205 (78.8%) was the most common sign. On ultrasound scan, lesions were mostly multifocal 175 (67.3%), and the median FibroScan score was 75 kPa. The median fibrosis 4 and aspartate transferase platelet ratio index were 4.6 and 2.2, respectively. Hepatitis B surface antigen (HBsAg) was positive in 170 (65.4%) patients, and the median AFP level was 3263 ng/ml. HCC patients with positive HBsAg were more likely to be male 145 (85.3%) vs 62 (72.1%) (p = 0.011), much younger 39.9 vs 51.4 yrs (p =  < 0.0001), more likely to have abdominal pain 156 (91.8%) vs 68 (79.1%) (p = 0.002), jaundice 78 (45.9%) vs 29 (33.7%) (p = 0.042), dark urine 117 (68.8%) vs 46 (53.5%) (p = 0.018), raised transaminases (Aspartate transaminases 224.5 (32–7886) vs 153 (18–610), p =  < 0.01, Alanine transferases 71 (5–937) vs 47 (8–271), p =  < 0.001) and decreased platelet count 207 (33–941) vs 252 (52- 641) (p = 0.021) compared to patients with HCC who were HBsAg-negative. Conclusions The prognosis of patients with HCC is poor in developing countries such as The Gambia, where screening programs and treatment modalities are scarce. Young males are disproportionately affected, and HBV is a major cause of HCC in The Gambia

Cost-effectiveness of community-based screening and treatment for chronic hepatitis B in The Gambia: an economic modelling analysis

Background: Despite the high burden of hepatitis B virus (HBV) infection in sub-Saharan Africa, absence of widespread screening and poor access to treatment leads to most people remaining undiagnosed until later stages of disease when prognosis is poor and treatment options are limited. We examined the cost-effectiveness of community-based screening and early treatment with antiviral therapy for HBV in The Gambia. Methods: In this economic evaluation, we combined a decision tree with a Markov state transition model to compare a screen and treat intervention consisting of adult community-based screening using a hepatitis B surface antigen (HBsAg) rapid test and subsequent HBV antiviral therapy versus current practice, in which there is an absence of publicly provided screening or treatment for HBV. We used data from the PROLIFICA study to parameterise epidemiological, primary screening, and cost information, and other model parameter inputs were obtained from a literature search. Outcome measures were cost per disability-adjusted life-year (DALY) averted; cost per life-year saved; and cost per quality-adjusted life-year (QALY) gained. We calculated the incremental cost-effectiveness ratios (ICERs) between current practice and the screen and treat intervention. Costs were assessed from a health provider perspective. Costs (expressed in 2013 US$) and health outcomes were discounted at 3Findings: In The Gambia, where the prevalence of HBsAg is 8·8$540 per DALY averted, $645 per life-year saved, and$511 per QALY gained, compared with current practice. These ICERs are in line with willingness-to-pay levels of one times the country's gross domestic product per capita ($487) per DALY averted, and remain robust over a wide range of epidemiological and cost parameter inputs. Interpretation: Adult community-based screening and treatment for HBV in The Gambia is likely to be a cost-effective intervention. Higher cost-effectiveness might be achievable with targeted facility-based screening, price reductions of drugs and diagnostics, and integration of HBV screening with other public health interventions. Funding: European Commission

Flow diagram of the study population.

<p>Flow diagram of the study population.</p